Run-time executives and operating system kernels for embedded systems have long relied exclusively on static priority scheduling of tasks to ensure timing constraints and other correctness conditions are met. Static priority scheduling is easy to understand and support but it suffers from a number of significant shortcomings such as the complexity of simultaneously mapping timing and importance...

Operating room scheduling is an important task in healthcare sector. This study proposes a Mixed Integer Nonlinear Programming (MINLP) mathematical model for the scheduling of the operating rooms. In the presented model, apart from scheduling the patients’ surgery process, shifting of the medical staff is also carried out. The innovation considered in the proposed model is aimed at prioritizing...

In this paper we present a dynamic bandwidth allocation algorithm for EPON, which makes use of the Multipoint Control Protocol (MPCP) with threshold reporting and with interand intra-ONU priority scheduling. Three varieties of this algorithm are compared, by means of a detailed simulation program, regarding average packet delay for several priorities, delay variation for constant bit rate (CBR)...

The Stack Resource Policy (SRP) is a resource allocation policy which permits processes with different priorities to share a single runtime stack. It is a refinement of the Priority Ceiling Protocol (PCP) of Sha, Rajkumar and Lehoczky, which strictly bounds priority inversion and permits simple schedulability tests. With or without stack sharing, the SRP offers improvements over the PCP, by: (1...

We introduce a new class of policies for stochastic project scheduling with resource constraints, the linear preselective policies. They combine the benefits of two known classes of scheduling policies for stochastic and deterministic scheduling, viz. priority policies and preselective policies. Priority policies solve resource conflicts by means of a priority list (list scheduling). They have ...

This paper aims to develop a multi-objective model for scheduling cargo trains faced by the costs of tardiness and earliness, time limitations, queue priority and limited station lines. Based upon the Islamic Republic of Iran Railway Corporation (IRIRC) regulations, passenger trains enjoy priority over other trains for departure. Therefore, the timetable of cargo trains must be determined based...

The problem of real-time scheduling spans a broad spectrum of algorithms from simple uniprocessor to highly sophisticated multiprocessor scheduling algorithms. In this paper, we study the characteristics and constraints of real-time tasks which should be scheduled to be executed. Analysis methods and the concept of optimality criteria, which leads to design appropriate scheduling algorithms, wi...

This paper presents the Fixed Priority until Critical Laxity (FPCL) and Fixed Priority until Zero Laxity (FPZL) and scheduling algorithms for multiprocessor real-time systems. FPZL is similar to global fixed priority pre-emptive scheduling; however, whenever a task reaches a state of zero laxity it is given the highest priority. FPCL is a variant of FPZL that introduces no additional scheduling...

The purpose of this paper is to investigate the issues related to task attribute assignment on an individual processor. The majority of papers on fixed priority scheduling make the assumption that tasks have their attributes (deadline, period, offset and priority) pre-assigned. This makes priority assignment trivial. However in practice, the system’s timing requirements are specified and it is ...

Fixed-Priority Scheduling with Deferred Preemption (FPDS) is a middle ground between Fixed-Priority Preemptive Scheduling and Fixed-Priority Non-preemptive Scheduling, and offers advantages with respect to context switch overhead and resource access control. In this paper we present our work on extending the realtime operating system RTAI/Linux with support for FPDS. We give an overview of poss...